PostgreSQL or mySQL

Hello List:

I hope my question does not start war of the posts. This question is
genuine. Please answer objectively:

I am test setting a Master Server (MS) with CentOS 4.3, freeRADIUS, DNS,
Apache, (mySQL & PostgreeSQL), PHP, Postfix, etc. This Master Server will
have all the software I we need for our operation. We will copy MS to each
server and setup a load balancing servers.

I have very little knowledge of either PostgreeSQL or mySQL. Please advise
me as to which of these two software package to use? I need some specific
examples as to superiority of one package over the other. I prefer using the
package which has a goof GUI database design.

Please help. I am posting this message to both lists. I am specifically
interested in opinion of system analysts who have used both of these
packages.

Thanks.

Kirti